Supercritical carbon dioxide and electric in-situ leaching method and system for sandstone type uranium ore

Abstract

The invention discloses a supercritical carbon dioxide and electric in-situ leaching method and system for sandstone type uranium ore, and relates to the field of uranium ore mining. The invention relates to a supercritical carbon dioxide and electric in-situ leaching method for sandstone type uranium ore. The method comprises the following steps: perforating a liquid injection well and an extraction well and acquiring geologic condition parameters of in-situ immersion hydrology; pressurizing and heating carbon dioxide to form supercritical carbon dioxide, mixing the supercritical carbon dioxide with in-situ immersion liquid, and injecting into a liquid injection well; microwaves are emitted into the liquid injection well and the extraction well to heat the surrounding rock; carbon dioxide, oxygen and filtered underground water are prepared into treating fluid suitable for the target stratum, and the treating fluid is injected into the liquid injection well at the preset temperature and pressure; respectively electrifying the liquid injection well and the extraction well to generate electric field directional migration and uranium element enrichment for preset time; and the ore leaching liquid in the extraction well is extracted, and the third to sixth steps are repeated. According to the supercritical carbon dioxide and electric in-situ leaching method and system for the sandstone type uranium ore, microwave heating of leaching liquid is combined with external electric field enhanced migration, the leaching time of uranium ions is shortened, and the extraction efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of uranium mining, in particular, relates to a sandstone type uranium supercritical carbon dioxide and electric in-situ leaching method and system. BACKGROUND

[0002] Uranium resources are the key material basis for nuclear power development and are irreplaceable national scarce strategic resources. More than 90% of China's total natural uranium production capacity comes from sandstone type uranium in-situ leaching mining, among which CO2 and O2 neutral leaching uranium mining technology is the main mining technology. Although CO2 and O2 leaching method is beneficial to the development of low-grade sandstone type uranium, but CO2 and O2 in-situ leaching process is faced with limited leaching liquid wave range, ore layer plugging, low solute transport efficiency and other key problems. Therefore, not only the chemical leaching method is needed to improve the leaching rate of uranium, but also the uranium reservoir needs to be permeability improved, so as to convert 70% of the dense sandstone uranium into high mining value live ore and improve China's uranium production capacity.

[0003] Supercritical carbon dioxide extraction is a new type of environmentally friendly leaching method. In supercritical state, carbon dioxide has a special leaching effect on uranium in uranium ore, and has stronger permeability to low permeability objects, so it can selectively extract components with different polarity, boiling point and molecular weight. However, the existing sandstone type uranium supercritical carbon dioxide in-situ leaching method and system still have the problem of low extraction efficiency. SUMMARY

[0004] The purpose of the present application is to provide a sandstone type uranium supercritical carbon dioxide and electric in-situ leaching method and system, which can reduce the leaching time of uranium ions, avoid high concentration accumulation of anion oxidizing agent, reduce the occurrence of oxidizing agent side reaction, significantly improve the utilization rate of raw materials, increase the concentration of leaching liquid and reduce the production cycle, and improve the extraction efficiency.

[0005] The present application is realized as follows: The present application provides a sandstone type uranium supercritical carbon dioxide and electric in-situ leaching method, comprising the following steps: S1, perforating the injection well and the extraction well in the uranium-containing aquifer and obtaining the in-situ leaching hydrogeological condition parameters; S2, pressurizing and heating carbon dioxide to form supercritical carbon dioxide, and mixing the supercritical carbon dioxide with the in-situ leaching liquid and injecting the mixture into the injection well; S3, emitting microwaves to heat the surrounding rock in the injection well and the extraction well, detecting the temperature of the injection well and the extraction well to obtain a temperature cloud picture, and adjusting the microwave power according to the temperature cloud picture; S4, configuring carbon dioxide, oxygen and filtered underground water into a treatment liquid suitable for the target stratum, and injecting the treatment liquid into the injection well at a preset temperature and pressure; S5, generating an electric field by electrifying the injection well and the extraction well to accelerate the directional migration and enrichment of the uranium elements in the sandstone uranium mine, and maintaining a preset time; S6, extracting the leaching solution from the extraction well, and repeating steps S2-S5.

[0006] In some optional embodiments, the in-situ leaching hydrogeological condition parameters include the ore-bearing aquifer thickness, ion type, water conductivity coefficient, and water inflow.

[0007] In some optional embodiments, when the carbon dioxide is pressurized and heated to form supercritical carbon dioxide, the pressure compensation and temperature compensation of the supercritical carbon dioxide are performed based on the burial depth of the uranium-bearing aquifer.

[0008] In some optional embodiments, when the microwaves are emitted for heating in the injection well and the extraction well, the output power for generating effective microwave heat radiation to the uranium-bearing aquifer is calculated and adjusted to the required output power.

[0009] In some optional embodiments, when the carbon dioxide, oxygen, and filtered underground water are configured into a treatment fluid suitable for the target formation, the molar concentration of the ions at time t is calculated and adjusted to the required molar concentration. In some optional embodiments, when the cathode electrode rods and the anode electrode rods arranged in the injection well and the extraction well are electrified to generate an electric field to accelerate the directional migration and enrichment of the uranium elements in the sandstone uranium mine, the total flux of the charged substances at time t is calculated and adjusted to the required total flux.

[0010] In some optional embodiments, when the cathode electrode rods and the anode electrode rods arranged in the injection well and the extraction well are electrified to generate an electric field to accelerate the directional migration and enrichment of the uranium elements in the sandstone uranium mine, the total flux of the charged substances at time t is calculated and adjusted to the required total flux.

[0011] In some optional embodiments, when the cathode electrode rods and the anode electrode rods arranged in the injection well and the extraction well are electrified to generate an electric field to accelerate the directional migration and enrichment of the uranium elements in the sandstone uranium mine, the total flux of the charged substances at time t is calculated and adjusted to the required total flux.

[0012] In some optional embodiments, when the cathode electrode rods and the anode electrode rods arranged in the injection well and the extraction well are electrified to generate an electric field to accelerate the directional migration and enrichment of the uranium elements in the sandstone uranium mine, the electrode chamber in which the cathode electrode rods and the anode electrode rods are located is taken as a liquid storage chamber, the molar concentration of the ions in the electrode chamber at time t is calculated and adjusted to the required molar concentration.

[0013] ​​​​​In some alternative embodiments, when the cathode electrode rod and the anode electrode rod arranged in the injection well and the extraction well are powered to generate an electric field to accelerate the directional migration and enrichment of uranium elements in the sandstone uranium mine, the electrode chamber in the region where the cathode electrode rod and the anode electrode rod are arranged is used as a liquid storage chamber, and the molar concentration of ions in the electrode chamber is calculated and adjusted.

[0014] In some alternative embodiments, before the cathode electrode rod and the anode electrode rod arranged in the injection well and the extraction well are powered to generate an electric field, the temperature of the treatment liquid is controlled to be in the range of 40-80℃, and the pressure is above 7.29MPa.

[0015] In some alternative embodiments, when the cathode electrode rod and the anode electrode rod arranged in the injection well and the extraction well are powered to generate an electric field to accelerate the directional migration and enrichment of uranium elements in the sandstone uranium mine, the microwave power is simultaneously increased to increase the temperature of the uranium-containing aquifer to 40-200℃ and maintain for 15-60 days.

[0016] The application also provides a sandstone-type uranium mine supercritical carbon dioxide and electric in-situ leaching system, which comprises: a supercritical carbon dioxide injection system for generating supercritical carbon dioxide; an electric system for powering the injection well and the extraction well to generate an electric field to accelerate the directional migration and enrichment of uranium elements in the sandstone uranium mine; a microwave heating system for microwave heating the injection well and the extraction well; an in-situ leaching system for mixing the in-situ leaching liquid with the supercritical carbon dioxide generated by the supercritical carbon dioxide injection system and then conveying the mixture to the injection well and extracting the leaching liquid from the extraction well.

[0017] In some alternative embodiments, the supercritical carbon dioxide injection system comprises a carbon dioxide storage tank, a booster pump, a heater and an in-situ leaching liquid storage tank connected by an injection pipeline.

[0018] In some alternative embodiments, the electric system comprises an electrolyte treatment and storage device, a cathode pipeline, a cathode electrode rod connected to the cathode pipeline, a cathode filter screen wrapping the cathode pipeline and the cathode electrode rod, an anode pipeline, an anode electrode rod connected to the anode pipeline, an anode filter screen wrapping the anode pipeline and the anode electrode rod, and a power distribution device, wherein the electrolyte treatment and storage device is connected to the cathode pipeline, the anode pipeline and the power distribution device, respectively.

[0019] ​​In some alternative implementations, the microwave heating system includes at least two microwave tubes, at least two microwave antennas, at least two coaxial waveguides, a waveguide transducer, a rectangular waveguide, and a microwave generator. Each microwave tube contains at least one coaxial waveguide, each coaxial waveguide is connected to a microwave antenna, the coaxial waveguide is connected to the waveguide transducer, the waveguide transducer is connected to the microwave generator through the rectangular waveguide, and multiple infrared thermal imagers are connected to the outer wall of each microwave tube.

[0020] In some alternative implementations, the ground leaching system includes a filter, a carbon dioxide pressurizing device, an oxygen pressurizing device, a ground leaching injection pipeline, a ground leaching extraction pipeline, a storage tank, and an extraction tank. The filter, carbon dioxide pressurizing device, and oxygen pressurizing device are respectively connected to the storage tank, the storage tank is connected to the ground leaching injection pipeline, and the ground leaching extraction pipeline is connected to the extraction tank.

[0021] The beneficial effects of this application are as follows: The supercritical carbon dioxide and electro-electric in-situ leaching method for sandstone-type uranium deposits provided in this application includes the following steps: perforating injection wells and extraction wells in the uranium-bearing aquifer and obtaining geogeological parameters of the in-situ leaching; pressurizing and heating carbon dioxide to form supercritical carbon dioxide, then mixing it with the in-situ leaching solution and injecting it into the injection wells; emitting microwaves into the injection wells and extraction wells to heat the surrounding rock, detecting the temperature of the injection wells and extraction wells and processing it to obtain temperature cloud maps, adjusting the microwave power according to the temperature cloud maps; preparing a treatment solution suitable for the target formation by mixing carbon dioxide, oxygen, and filtered groundwater and injecting it into the injection wells at a preset temperature and pressure; energizing the injection wells and extraction wells to generate an electric field to accelerate the directional migration and enrichment of uranium elements in the sandstone uranium deposits, maintaining this for a preset time; extracting the leaching solution from the extraction wells, and repeating steps three to six. The supercritical carbon dioxide and electrokinetic in-situ leaching method and system for sandstone-type uranium ore provided in this application enhances migration by combining microwave heating of the leaching solution with an external electric field, reducing the leaching time of uranium ions, avoiding high-concentration accumulation of anionic oxidants, reducing the occurrence of oxidant side reactions, significantly improving raw material utilization, increasing leaching solution concentration, reducing production cycle, and improving extraction efficiency. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic flowchart of the supercritical carbon dioxide and electrokinetic in-situ leaching method for sandstone-type uranium ore provided in this application embodiment; Figure 2A partial structural schematic diagram of a supercritical carbon dioxide and electro-electric in-situ leaching system for sandstone-type uranium deposits provided in an embodiment of this application; Figure 3 A partial structural diagram of the supercritical carbon dioxide and electric in-situ leaching system for sandstone-type uranium deposits provided in this application embodiment, located in the injection well. Figure 4 This is a partial structural diagram of the supercritical carbon dioxide and electric in-situ leaching system for sandstone-type uranium deposits provided in this application embodiment, located in the extraction well.

[0024] In the diagram: 100, Supercritical carbon dioxide injection system; 110, Injection pipeline; 120, Carbon dioxide storage tank; 130, Booster pump; 140, Heater; 150, Infiltration solution storage tank; 200, Electrical system; 210, Electrolyte treatment and storage device; 220, Cathode pipeline; 230, Cathode electrode rod; 240, Cathode filter; 250, Anode pipeline; 260, Anode electrode rod; 270, Anode filter; 280, Power distribution device; 300, Microwave heating system; 310, Microwave protective tube; 3 20. Microwave antenna; 330. Coaxial waveguide; 340. Waveguide converter; 350. Rectangular waveguide; 360. Microwave generator; 370. Infrared thermal imager; 400. Ground immersion system; 410. Filter; 420. Carbon dioxide pressurization device; 430. Oxygen pressurization device; 440. Ground immersion injection pipeline; 450. Ground immersion extraction pipeline; 460. Storage tank; 470. Extraction tank; 480. Extraction pump; 500. Injection well; 600. Extraction well; 700. Packer; 710. Support frame. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0028] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0030] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] The following detailed description of the features and performance of the supercritical carbon dioxide and electro-electric in-situ leaching system and method for sandstone-type uranium deposits of this application, in conjunction with embodiments, provides further insight into their characteristics and performance.

[0033] like Figure 2 , Figure 3 and Figure 4As shown in the embodiments of this application, a supercritical carbon dioxide and electric in-situ leaching system for sandstone-type uranium ore is also provided. This system includes a supercritical carbon dioxide injection system 100, an electric system 200, a microwave heating system 300, and an in-situ leaching system 400. The supercritical carbon dioxide injection system 100 generates supercritical carbon dioxide. The electric system 200 energizes the injection well 500 and the extraction well 600 to generate an electric field that accelerates the directional migration and enrichment of uranium in the sandstone uranium ore. The microwave heating system 300 microwaves the injection well 500 and the extraction well 600. The in-situ leaching system 400 mixes the in-situ leaching solution with the supercritical carbon dioxide generated by the supercritical carbon dioxide injection system and then delivers the mixture to the injection well 500 and extracts the leaching solution from the extraction well 600.

[0034] The supercritical carbon dioxide injection system 100 includes a carbon dioxide storage tank 120, a booster pump 130, a heater 140, and a ground leaching solution storage tank 150, which are connected by an injection pipeline 110. The ground leaching solution storage tank 150 is connected to the injection well 500 through the injection pipeline 110. The injection pipeline 110 is equipped with valves upstream and downstream of the booster pump 130 and the heater 140 for control.

[0035] The electric system 200 includes an electrolyte treatment and storage device 210, a cathode line 220, a cathode electrode rod 230 connected to the cathode line 220, a cathode filter 240 enclosing the cathode line 220 and the cathode electrode rod 230, an anode line 250, an anode electrode rod 260 connected to the anode line 250, an anode filter 270 enclosing the anode line 250 and the anode electrode rod 260, and a power distribution device 280. The electrolyte treatment and storage device 210 is connected to the cathode line 220, the anode line 250, and the power distribution device 280, respectively. The cathode filter 240 and the anode filter 270 respectively form a cathode chamber and an anode chamber. The electrolyte treatment and storage device 210 includes an electrolysis device and an electrolyte storage tank. The electrolysis device is used to electrically connect to the cathode electrode rod 230 and the anode electrode rod 260 through the cathode line 220 and the anode line 250, respectively, to form a cathode and an anode. The electrolyte storage tank is connected to the cathode line 220 and the anode line 250 respectively for introducing the electrolyte solution into the cathode chamber and the anode chamber via the cathode line 220 and the anode line 250. The cathode line 220 includes a cathode wire connecting to the electrolysis device and a cathode electrolyte pipe connecting to the electrolyte storage tank. The anode line 250 includes an anode wire connecting to the electrolysis device and an anode electrolyte pipe connecting to the electrolyte storage tank.

[0036] The microwave heating system 300 includes two microwave tubes 310, two microwave antennas 320, two coaxial waveguides 330, a waveguide converter 340, a rectangular waveguide 350, and a microwave generator 360. Each microwave tube 310 contains a coaxial waveguide 330. A microwave antenna 320 is connected to the bottom of each coaxial waveguide 330. The top of the coaxial waveguide 330 extends out of the microwave tube 310 and is connected to the waveguide converter 340. The waveguide converter 340 is connected to the microwave generator 360 through the rectangular waveguide 350. Infrared thermal imagers 370 are connected to the outer wall of each microwave tube 310 at intervals.

[0037] The ground leaching system 400 includes a filter 410, a carbon dioxide pressurizing device 420, an oxygen pressurizing device 430, a ground leaching injection pipeline 440, a ground leaching extraction pipeline 450, a storage tank 460, and an extraction tank 470. The filter 410, carbon dioxide pressurizing device 420, and oxygen pressurizing device 430 are connected to the storage tank 460 via pipelines. The storage tank 460 is connected to the ground leaching injection pipeline 440. The ground leaching extraction pipeline 450 is connected to the extraction tank 470. A pump 480 is installed on the liquid pipeline 450. The leaching liquid pipeline 450 is connected to the extraction well 600. The storage tank 460 is connected to the booster pump 130, the heater 140, and each injection well 500 in sequence through the leaching liquid injection pipeline 440. That is, the supercritical carbon dioxide injection system 100 and the leaching system 400 share the booster pump 130 and the heater 140. The leaching liquid injection pipeline 440 is equipped with valves upstream and downstream of the booster pump 130 and the heater 140 for control. In other optional embodiments, the leaching system 400 can also use a single booster pump and a heating device. In this case, the storage tank 460 can be connected to the booster pump and the heating device in sequence through the leaching liquid injection pipeline 440 and then connected to each injection well 500.

[0038] In some optional embodiments, the length of the anode electrode rod 260 and the cathode electrode rod 230 is 50-400m. The anode electrode rod 260 and the cathode electrode rod 230 are one of metal electrodes, graphite electrodes, and ceramic electrodes. The surfaces of the anode electrode rod 260 and the cathode electrode rod 230 are treated with insulation and anti-corrosion, and the surfaces of the anode electrode rod 260 and the cathode electrode rod 230 are coated with an insulating layer and an anti-corrosion layer.

[0039] In some alternative embodiments, the length of the anode filter 270 and the cathode filter 240 is 50-500m, and the anode filter 270 and the cathode filter 240 are one of nickel mesh, titanium mesh, nylon mesh, and polypropylene mesh, and the mesh count of the mesh is above 200 mesh.

[0040] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown in the embodiments of this application, a method for supercritical carbon dioxide and electrokinetic in-situ leaching of sandstone-type uranium ore is also provided. This method utilizes the aforementioned supercritical carbon dioxide and electrokinetic in-situ leaching system for sandstone-type uranium ore and includes the following steps: Step S1: Drill a 500 injection well and a 600 extraction well into the uranium-bearing aquifer and cement the wells to complete the well. The leaching units of injection well 500 and extraction well 600 are one of the following: two-point type, four-injection-one-extraction type, six-injection-one-extraction type, and six-injection-two-extraction type. In addition, injection well 500 and extraction well 600 can be swapped during the leaching process to avoid the formation of acidic and alkaline zones in injection well 500 and extraction well 600, which would lead to chemical precipitation, causing precipitation to adsorb uranyl ions and reduce the permeability of the deposit.

[0041] The distance (L) between injection well 500 and extraction well 600 is 25-52m. After borehole enlargement, the diameter of injection well 500 is 200-255mm, and the diameter of extraction well 600 is 89-255mm. The pumping rate of extraction well 600 is 0-35m / s. 3 / h.

[0042] Step S2: Perforate the injection wells and extraction wells in the uranium-bearing aquifer and obtain the in-situ leaching hydrogeological parameters of the sandstone-type uranium deposit; the in-situ leaching hydrogeological parameters include the thickness of the ore-bearing aquifer, ion type, hydraulic conductivity, and water inflow.

[0043] A microwave protective tube 310 and a cathode filter 240 are placed into the injection well 500, and a microwave protective tube 310 and an anode filter 270 are placed into the extraction well 600. A microwave antenna 320 is connected to the front end of a coaxial waveguide 330 and placed inside the microwave protective tube 310. The rear end of the coaxial waveguide 330 is connected to a waveguide converter 340 on the surface. The waveguide converter 340 is connected to a microwave generator 360 via a rectangular waveguide 350. Infrared thermal imagers 370 are evenly connected between the uranium-bearing aquifers on the outer wall of the microwave protective tube 310. Infrared thermal imagers 370 are installed at even intervals starting from the bottom of the uranium-bearing aquifer. Each infrared thermal imager 370 is connected to the others via a high-strength, corrosion-resistant communication cable. Cable connection; connect one end of cathode line 220 to cathode electrode rod 230 and place it in cathode filter 240, connect the other end of cathode line 220 to electrolyte treatment and storage device 210, and connect electrolyte treatment and storage device 210 to power distribution device 280 for power supply; connect one end of anode line 250 to anode electrode rod 260 and place it in anode filter 270, and connect the other end of anode line 250 to electrolyte treatment and storage device 210; connect the tops of injection well 500 and extraction well 600 using packer 700; connect microwave protective tube 310 to the corresponding cathode filter 240 or anode filter 270 located in the same well through support frame 710; Step S3: Using a booster pump 130 and a heater 140, the carbon dioxide in the carbon dioxide storage tank 120 is pressurized and heated sequentially to form supercritical carbon dioxide, which is then introduced into the infiltration solution storage tank 150 and mixed with the infiltration solution. The mixture is then injected into the injection well 500 via the injection pipeline 110. The injection rate of the injection well 500 is 0-10 m / s². 3 / h.

[0044] When carbon dioxide is pressurized and heated to form supercritical carbon dioxide, compensation is based on the burial depth of the uranium-bearing aquifer, and the compensation pressure is calculated using the following formula. With compensation temperature : ; ; In the formula, This represents the drilling depth of the uranium deposit (0m is recorded at the surface, and negative values ​​are taken downwards). Indicates the location of the uranium deposit Formation pressure at depth; Indicates the location of the uranium deposit Formation temperature at depth; This represents the critical pressure at which carbon dioxide reaches supercriticality, i.e. ; This represents the critical temperature at which carbon dioxide reaches supercriticality, i.e. ; Indicates surface temperature; Indicates atmospheric pressure at the Earth's surface; Represents the geothermal gradient, taken as 25. ; Represents the formation pressure gradient, taken as 26. .

[0045] Step S4: Turn on the microwave generator 360 to generate microwaves, which are then transmitted sequentially through the rectangular waveguide 350, waveguide converter 340, and coaxial waveguide 330 to the microwave antenna 320. The generated microwave thermal radiation is conducted to the surrounding rock of the uranium-bearing aquifer to heat the injection well 500 and the extraction well 600. Supercritical carbon dioxide is coupled to create fissures and fractures in the uranium-bearing aquifer. The temperature of the injection well 500 and the extraction well 600 is detected by the infrared thermal imager 370 and processed to obtain a temperature cloud map. The microwave power is adjusted according to the temperature cloud map. When emitting microwave heating in injection well 500 and extraction well 600, the output power of effective microwave thermal radiation to the uranium-bearing aquifer is calculated using the following formula: ; In the formula, This indicates the spatial coordinates of the fluid within the uranium-bearing aquifer of the uranium deposit. The density of the fluid; This represents the compensated temperature after heating the uranium-bearing aquifer, which is the temperature detected at the current spatial location minus the original formation temperature. This represents the specific heat capacity of the fluid, which is related to temperature changes, and is taken as 4200 J / (kg·K). This represents the volume of the microwave radiation range calculated based on the detection by the infrared thermal imager. It is in time The temperature difference between the hot fluid in the fissure and fracture regions subjected to microwave thermal radiation at the injection well and the extraction well; Indicates the thermal fluid in time Darcy's speed at that time; among which, and It can be described as: ; ; In the formula, This indicates the spatial coordinates of the fluid within the uranium-bearing aquifer of the uranium deposit. Indicates time The temperature of the hot fluid in the gaps and fissures; The density of the fluid; This represents the specific heat capacity of the fluid, which is related to temperature changes, and is taken as 4200 J / (kg·K). Indicates the hydraulic conductivity; It is in time The temperature difference between the hot fluid in the fissure and fracture regions subjected to microwave thermal radiation at the injection well and the extraction well; This represents a gradient operator restricted to the tangential plane of the crack and fissure; The drilling depth of the uranium deposit in question; Indicates the location of the uranium deposit Formation pressure at depth; Indicates the length between the injection well and the extraction well; It represents the acceleration due to gravity.

[0046] Step S5: After filtering the groundwater heated to a preset temperature using filter 410, the water is introduced into storage tank 460. Carbon dioxide pressurization device 420 and oxygen pressurization device 430 are used to pressurize carbon dioxide and oxygen respectively and then introduce them into storage tank 460. The carbon dioxide, oxygen and filtered groundwater in storage tank 460 are mixed to form a treatment solution suitable for the target formation. The solution is then injected into the injection well at a preset temperature and pressure. The temperature range of the treatment solution is controlled to be 40-80℃ and the pressure is above 7.29MPa.

[0047] When preparing a treatment solution suitable for the target formation using carbon dioxide, oxygen, and filtered groundwater, the following formula is used to calculate the time. Time ions molar concentration : ; In the formula, Indicates the first uranium-bearing aquifer The diffusion coefficient of each ion; Indicates the porosity of a uranium-bearing aquifer; Indicates the thermal fluid in time Darcy's speed at that time; Let J represent the ideal gas constant, taken as 8.314 J / (mol·K); Indicates the location of the uranium deposit Formation temperature at depth Indicates the location of the uranium deposit Formation pressure at depth This indicates the rate of chemical reaction between supercritical carbon dioxide and the treatment liquid during in-situ leaching. For carbon dioxide and oxygen in the heat flow over time The partial molar volume at that time (which can be calculated using the ideal gas formula).

[0048] Calculate using the following formula and : ; ; In the formula, , and denoted by Langmuir volume constants for supercritical carbon dioxide, carbon dioxide, and oxygen, respectively; , and These represent the Langmuir pressure constants for supercritical carbon dioxide, carbon dioxide, and oxygen, respectively. , and These represent the partial pressures of supercritical carbon dioxide, carbon dioxide, and oxygen, respectively. ; Represents a specific reaction mechanism; For the first The Arabius pre-exponential factor of this reaction mechanism; For the first The apparent activation energy of a reaction mechanism; Indicates the initial mass of the precipitate phase; Indicates the mass of the precipitate; Let J represent the ideal gas constant, taken as 8.314 J / (mol·K); Indicates the location of the uranium deposit Formation temperature at depth Is it catalysis or inhibition of the first Aqueous ions with a certain reaction mechanism The activity, Indicating uranium-bearing aquifers The total number of ions. The expression represents the rate dependence of the dissolution reaction as a function of the Gibbs free energy; The surface area of ​​the treated liquid per unit volume; Calculate using the following formula :

[0049] In the formula, Ω is the mineral saturation entropy; Q is the reaction quotient; These are the equilibrium constants and two dimensionless fitting parameters. and s These are experience values, ranging from 1 to 3; It is the first Apparent activation energy of an ion.

[0050] Step S6: Using the electrolyte treatment and storage device 210, the cathode electrode rod 230 and anode electrode rod 260 in the injection well 500 and the extraction well 600 are respectively energized to generate an electric field to accelerate the directional migration and enrichment of uranium elements in sandstone uranium ore, and increase the microwave power to raise the temperature of the uranium-bearing aquifer to 40-200℃ and maintain it for 15-60 days.

[0051] When the cathode electrode rod 230 and anode electrode rod 260 located in injection well 500 and extraction well 600 are energized to generate an electric field that accelerates the directional migration and enrichment of uranium in sandstone uranium ore, the charged matter in time... The total flux at that time is calculated using the following formula: ; In the formula, Indicates the first uranium-bearing aquifer The diffusion flux of each ion; Indicates the first uranium-bearing aquifer The activity gradient flux of each ion; Indicates the first uranium-bearing aquifer The transport flux of each ion; The first uranium-bearing aquifer The flux of each ion; Indicates the first uranium-bearing aquifer The molar concentration of each ion; Indicates the first uranium-bearing aquifer The diffusion coefficient of each ion; Indicates the first uranium-bearing aquifer The valence state of each ion; Denotes Faraday's constant; Represents the potential gradient; Represents electrostatic potential; Indicates the porosity of a uranium-bearing aquifer; Indicates electroosmotic rate; Let J represent the ideal gas constant, taken as 8.314 J / (mol·K); Indicates the hydraulic conductivity; Indicates the dynamic viscosity of a fluid; The drilling depth of the uranium deposit is given. Indicates the location of the uranium deposit Formation temperature at depth; The first in the uranium-bearing aquifer The reactive power source / sink of an ion.

[0052] The following formula is used to calculate the time of charged matter. Current density corresponding to the total flux at time : ; In the formula, This represents the total flux of charged ions in a uranium-bearing aquifer. Indicating uranium-bearing aquifers The total number of ions; Indicates the first uranium-bearing aquifer The diffusion coefficient of each ion; Indicates the first uranium-bearing aquifer The molar concentration of each ion; Indicates the first uranium-bearing aquifer The valence state of each ion; Denotes Faraday's constant; Represents the potential gradient; Represents electrostatic potential; Indicates the porosity of a uranium-bearing aquifer; Indicates electroosmotic rate; Let J represent the ideal gas constant, taken as 8.314 J / (mol·K); Indicates the hydraulic conductivity; Indicates the dynamic viscosity of a fluid; The drilling depth of the uranium deposit in question; Indicates the location of the uranium deposit Formation temperature at depth.

[0053] The electrode chamber is used as a liquid storage chamber, and the time in the electrode chamber is... Time ions molar concentration Calculate using the following formula: ; In the formula, It is the cross-sectional area of ​​the electrode chamber. It is the volume of the electrode chamber; and It is a stepwise function of adjusting the time for electrolyte flushing and refilling at the electrode chamber; it has the total flux of charged substances. The positive or negative sign indicates the flux entering or leaving the electrode chamber, respectively; and It is a specified time The flow rate during electrolyte flushing and refilling at the electrode chamber.

[0054] Based on uranium reserves before leaching The volume of leaching solution extracted each time from the extraction well (600). The uranium concentration in the volume of leaching solution extracted each time. Relationship estimates the cumulative uranium leaching rate : ; In the formula, N is the total number of extractions for well 600. It refers to the uranium reserves before leaching. It is the volume of leachate extracted from the well each time. It is the volume of leachate extracted from the well each time. The uranium concentration in it.

[0055] Step S7: Start the submersible pump to extract the leaching solution from extraction well 600, and repeat steps S3-S6. The pumping rate of extraction well 600 is 0-35m / s. 3 / h; Sampling tests are conducted on injection well 500 and extraction well 600 in each step of steps S6-S9. During this period, the leaching fluid sweep area can be increased by adjusting the injection and extraction mode and replacing the electrode rod, thereby improving the efficiency of leaching uranium extraction until the uranium concentration of the leaching fluid is lower than the industrial concentration requirement.

[0056] The supercritical carbon dioxide and electro-hydraulic in-situ leaching method and system for sandstone-type uranium ore provided in this application uses a mixture of supercritical carbon dioxide and in-situ leaching fluid as a fracturing fluid to leach into the formation structure. Microwave heating of the leaching solution and the application of an external electric field enhance ion migration and electroosmosis, thereby reducing uranium ion leaching time. This helps avoid high-concentration accumulation of anionic oxidants, reduces oxidant side reactions, fully utilizes the enhancing effect of anionic oxidants, reduces leaching agent usage, significantly improves raw material utilization, increases leaching solution concentration, and shortens the production cycle. It improves production efficiency and effectively achieves good uranium leaching. The method is low-cost, has minimal environmental impact, and is easy to implement, possessing high industrial application value. Furthermore, after leaching and mining are completed, carbon dioxide can be injected again to achieve carbon dioxide geological sequestration, resulting in good environmental benefits. This method diversifies in-situ leaching processes, stabilizes the fluid supply, and meets the needs of different in-situ leaching environments and construction processes.

[0057] Furthermore, the calculation time was calculated when preparing a treatment solution containing carbon dioxide, oxygen, and filtered groundwater suitable for the target formation. Time ions The molar concentration is adjusted to the required level, ensuring that the target uranium-bearing aquifer remains in a leaching-ready environment for an extended period. This guarantees efficient uranium leaching during in-situ leaching and prevents the reintroduction of precipitated ions (such as Cr) by the prepared treatment solution. 3+ Ca 2+ Mg 2+ (etc.) cementation and precipitation can cause blockage of the ore-bearing layer.

[0058] When the cathode and anode electrodes installed in the injection and extraction wells are energized to generate an electric field that accelerates the directional migration and enrichment of uranium in sandstone uranium deposits, the time of the charged material is calculated. Adjusting the total flux to the required level can avoid and reduce unnecessary charged ions (such as K+) during leaching. + Na + Fe 2+ Fe 3+ Repeated migration of charged ions (such as Ti) in an electric field, which modulates and increases coupling with the target uranium ion or accelerates the electric field migration efficiency. 2+ Ti 3+ Cu 2+ Au 3+ (etc.), thereby improving the leaching efficiency of the target uranium ions.

[0059] When the cathode and anode electrodes installed in the injection and extraction wells are energized to generate an electric field that accelerates the directional migration and enrichment of uranium in sandstone uranium deposits, the time of the charged material is calculated. The total flux corresponds to the current density and is adjusted to the required current density. Based on the total flux, the power loss required in the electro-leaching process can be effectively adjusted, and by adjusting the total flux to an appropriate value, the electro-in-situ leaching process can be promoted to be carried out with lower energy consumption and higher efficiency.

[0060] When the cathode and anode electrodes installed in injection and extraction wells are energized to generate an electric field that accelerates the directional migration and enrichment of uranium in sandstone uranium deposits, the electrode chambers in the areas where the cathode and anode electrodes are located are used as storage chambers. The time in the electrode chambers is calculated. Time ions Adjusting the molar concentration to the required level ensures efficient uranium leaching during electro-emergent in-situ leaching and avoids the precipitation of easily precipitated ions (such as Ca). 2+ Mg 2+ Long-term cementation and precipitation (etc.) further blockages the ore-bearing layer. Furthermore, the calculations based on the above formulas for each time period... Time ions The molar concentration can reveal the mineral oxidation-reduction dissolution-precipitation reaction mechanism of the electrodynamic in-situ leaching process.

[0061] In other alternative embodiments, to prevent the formation of alkaline and acidic regions in the cathode and anode regions of the injection well 500 and the extraction well 600, respectively, which would lead to the precipitation of heavy metal ions, a submersible pump can be used to circulate the liquid between the cathode and anode regions of the injection well 500 and the extraction well 600; or, sulfuric acid (H2SO4) and sodium hydroxide (NaOH) can be added to the injection well 500 and the extraction well 600, respectively, to adjust the pH value of the cathode and anode regions.

[0062] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A method for supercritical carbon dioxide and electrokinetic in-situ leaching of sandstone-type uranium ore, characterized in that, Includes the following steps: S1. Perforate injection wells and extraction wells in uranium-bearing aquifers and obtain geogeological parameters of in-situ leaching water. S2. Pressurize and heat carbon dioxide to form supercritical carbon dioxide, mix it with infiltration fluid, and inject it into the injection well; S3. Microwaves are emitted into the injection well and the extraction well to heat the surrounding rock. The temperature of the injection well and the extraction well is detected and processed to obtain a temperature cloud map. The microwave power is adjusted according to the temperature cloud map. S4. Prepare a treatment solution with carbon dioxide, oxygen and filtered groundwater to suit the target formation and inject it into the injection well at a preset temperature and pressure. S5. Electricity is applied to the injection well and extraction well to generate an electric field that accelerates the directional migration and enrichment of uranium in sandstone uranium deposits for a preset time. S6. Extract the leaching solution from the well and repeat steps S2-S5.

2. The supercritical carbon dioxide and electrokinetic in-situ leaching method for sandstone-type uranium deposits according to claim 1, characterized in that, The geological parameters of the in-situ leaching include the thickness of the mineral-bearing aquifer, ion type, hydraulic conductivity, and water inflow.

3. The supercritical carbon dioxide and electrokinetic in-situ leaching method for sandstone-type uranium ore according to claim 1, characterized in that, When supercritical carbon dioxide is formed by pressurizing and heating carbon dioxide, pressure and temperature compensation for supercritical carbon dioxide are performed based on the burial depth of the uranium-bearing aquifer.

4. The supercritical carbon dioxide and electrokinetic in-situ leaching method for sandstone-type uranium deposits according to claim 1, characterized in that, When emitting microwave heating to the injection well and the extraction well, the output power of generating effective microwave thermal radiation to the uranium-bearing aquifer is calculated and adjusted to the required output power.

5. The supercritical carbon dioxide and electrokinetic in-situ leaching method for sandstone-type uranium deposits according to claim 1, characterized in that, When preparing a treatment solution suitable for the target formation using carbon dioxide, oxygen, and filtered groundwater, the calculation time is... Time ions The molar concentration is determined and adjusted to the desired molar concentration.

6. The supercritical carbon dioxide and electrokinetic in-situ leaching method for sandstone-type uranium deposits according to claim 1, characterized in that, When an electric field is applied to the cathode and anode electrodes located in the injection and extraction wells, respectively, to accelerate the directional migration and enrichment of uranium in sandstone uranium deposits, the time-dependent changes in the charged matter are calculated. The total flux at that time is adjusted to the required total flux.

7. The supercritical carbon dioxide and electrokinetic in-situ leaching method for sandstone-type uranium ore according to claim 6, characterized in that, When an electric field is applied to the cathode and anode electrodes located in the injection and extraction wells, respectively, to accelerate the directional migration and enrichment of uranium in sandstone uranium deposits, the time-dependent changes in the charged matter are calculated. The total flux corresponds to the current density and is adjusted to the required current density.

8. The supercritical carbon dioxide and electrokinetic in-situ leaching method for sandstone-type uranium deposits according to claim 7, characterized in that, When an electric field is generated by energizing the cathode and anode electrodes located in the injection and extraction wells respectively to accelerate the directional migration and enrichment of uranium in sandstone uranium deposits, the electrode chambers in the areas where the cathode and anode electrodes are located are used as storage chambers, and the time in the electrode chambers is calculated. Time ions The molar concentration is determined and adjusted to the desired molar concentration.

9. The supercritical carbon dioxide and electrokinetic in-situ leaching method for sandstone-type uranium ore according to claim 1, characterized in that, Before energizing the cathode and anode electrode rods located in the injection and extraction wells to generate an electric field, the temperature of the treatment fluid is controlled within the range of 40-80℃ and the pressure is above 7.29MPa.

10. The supercritical carbon dioxide and electrokinetic in-situ leaching method for sandstone-type uranium deposits according to claim 1, characterized in that, When the cathode and anode electrodes installed in the injection and extraction wells are energized to generate an electric field that accelerates the directional migration and enrichment of uranium in sandstone uranium deposits, the microwave power is simultaneously increased to raise the temperature of the uranium-bearing aquifer to 40-200℃ and maintain it for 15-60 days.

11. A supercritical carbon dioxide and electro-pneumatic in-situ leaching system for sandstone-type uranium deposits, characterized in that, It includes: A supercritical carbon dioxide injection system is used to generate supercritical carbon dioxide. The electric system is used to generate an electric field by energizing the injection well and the extraction well to accelerate the directional migration and enrichment of uranium in sandstone uranium deposits; Microwave heating system for microwave heating of injection wells and extraction wells; The in-situ leaching system is used to mix the in-situ leaching solution with the supercritical carbon dioxide generated by the supercritical carbon dioxide injection system and then deliver the mixture to the injection well, and to extract the leaching solution from the extraction well.

12. The supercritical carbon dioxide and electro-electric in-situ leaching system for sandstone-type uranium deposits according to claim 11, characterized in that, The supercritical carbon dioxide injection system includes a carbon dioxide storage tank, a booster pump, a heater, and a ground leaching solution storage tank connected by an injection pipeline.

13. The supercritical carbon dioxide and electro-electric in-situ leaching system for sandstone-type uranium deposits according to claim 11, characterized in that, The electric system includes an electrolyte treatment and storage device, a cathode pipeline, a cathode electrode rod connected to the cathode pipeline, a cathode filter screen covering the cathode pipeline and the cathode electrode rod, an anode pipeline, an anode electrode rod connected to the anode pipeline, an anode filter screen covering the anode pipeline and the anode electrode rod, and a power distribution device. The electrolyte treatment and storage device is connected to the cathode pipeline, the anode pipeline, and the power distribution device, respectively.

14. The supercritical carbon dioxide and electro-pneumatic in-situ leaching system for sandstone-type uranium deposits according to claim 11, characterized in that, The microwave heating system includes at least two microwave tubes, at least two microwave antennas, at least two coaxial waveguides, a waveguide converter, a rectangular waveguide, and a microwave generator. Each microwave tube contains at least one coaxial waveguide, each coaxial waveguide is connected to one microwave antenna, the coaxial waveguide is connected to the waveguide converter, the waveguide converter is connected to the microwave generator through the rectangular waveguide, and multiple infrared thermal imagers are connected to the outer wall of each microwave tube.

15. The supercritical carbon dioxide and electro-electric in-situ leaching system for sandstone-type uranium deposits according to claim 11, characterized in that, The ground leaching system includes a filter, a carbon dioxide pressurizing device, an oxygen pressurizing device, a ground leaching injection pipeline, a ground leaching extraction pipeline, a storage tank, and an extraction tank. The filter, the carbon dioxide pressurizing device, and the oxygen pressurizing device are respectively connected to the storage tank. The storage tank is connected to the ground leaching injection pipeline, and the ground leaching extraction pipeline is connected to the extraction tank.

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